Merhaba,
Alt scroll dan bahsediyorsanız,
46, 47 satırlardaki style kullanmazsanız sorununuz çözülür.
footer {width:100%;}
aside .sidebar {width:100%;} <!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<title>Responsive Web Design</title>
<style type="text/css">
* {
padding:0;
margin:0;
list-style:none;
}
#wrapper {width:900px;margin:0 auto;}
header {
background:#c03;
}
header img {width:900px;}
nav ul#menu {background:#cf0;height:40px;font:12px tahoma;}
nav ul#menu li {float:left;}
nav ul#menu li a {text-decoration:none;display:block;line-height:40px;padding:0 15px;color:#333;}
nav ul#menu li a:hover {background:#fc0;}
content {width:680px;float:left;margin-top:30px;}
aside {width:200px;float:right;}
content article h2 a{font:bold 22px arial;text-decoration:none;color:#000;}
content article p {font:11px tahoma;line-height:24px;}
content article {margin-bottom:20px;}
aside {margin-top:30px;}
aside .sidebar {margin-bottom:15px;background:#f0f0f0;border:1px solid #ddd;padding:15px;border-radius:5px;}
aside .sidebar h2 {font:bold 20px arial;margin-bottom:5px;}
aside .sidebar p {line-height:22px;font:12px tahoma;}
.clear {clear:both;}
footer {background:#f0f0f0;border:1px solid #ddd;padding:10px;}
footer p {font:12px tahoma;}
@media (max-width:700px){
#wrapper {width:100%;}
header {width:100%;}
.banner {width:100%}
nav ul#menu {width:100%;height:auto;}
nav ul#menu li {float:none;}
nav ul#menu li a {border-bottom:1px solid #fff;text-align:center;}
content {width:100%;float:none;}
article {width:100%;}
article p ,aside p,footer p {color:#c03;}
aside {width:100%;float:none;}
}
</style>
</head>
<body>
<div id="wrapper">
<header>
<img src="resim.png" alt="manzara" class="banner"/>
</header>
<nav>
<ul id="menu">
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
<li><a href="#">Deneme</a></li>
</ul>
</nav>
<content>
<article>
<h2><a href="#">Başlık 1</a></h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
</p>
</article>
<article>
<h2><a href="#">Başlık 1</a></h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
</p>
</article>
</content>
<aside>
<div class="sidebar">
<h2>Sidebar Alan 1</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry.</p>
</div>
<div class="sidebar">
<h2>Sidebar Alan 1</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry.</p>
</div>
<div class="sidebar">
<h2>Sidebar Alan 1</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry.</p>
</div>
</aside>
<div class="clear"></div>
<footer>
<p>Tüm hakları saklıdır filan falan bla bla</p>
</footer>
</div>
</body>
</html>